central heating de-gunker fluid

If anyone can tell me the name of the company / product that you use
to treat heating systems that have got a bit blocked (black gunk) I'd
appreciate it!
I read about it here but can't remember the name.
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Give it a good flushing to get rid of the really loose stuff first. (Drain it and re-fill several times)
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Thankyou very much!
I've been looking for advice on this as its a sealed system but everywhere says "get a professional". Is it really that dodgy? Are their safety concerns (wouldn't have thought so).
I was going to tackle it like this.
Attach hose to drain cock then begin drain. Open air valves on upstairs rads until there is no more flow.
Close upstairs air valves. Open downstairs air valves and refill from water inlet until bottom of system is full. Close downstairs air valves and open upstairs ones then fill up system.
Then repeat as you suggested and then fill using the F3 cleaner stuff and follow their procedure.
Anything wrong with this approach?
Cheers, Rich.
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"RichGK" wrote
From experience, this has limited effect on badly fouled systems. Recommend Andy Hall's method: Take off all rads and flush them through with hose until clear (invert rad several times while flushing) Run water off at every rad valve/bleed point until clear If possible hook mains water up to the system and force gunge out (careful not to over pressure system/boiler doing this). Once you've done this and flushed the whole system several times, then run the cleaner through. Flush well again, add inhibitor and sit back knowing your system is tip-top. Use only Fernox IMHO, others are cheap second place
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In an earlier contribution to this discussion,
Most of the sludge will have accummulated in the radiators, and it will take a long time to wash it out by this method.
An alternative is to remove the radiators, and take them outside and give them a thorough wash out with a hose pipe. While each one is off, you can wash out its pipework by opening each radiator valve in turn (with a receptacle under it to catch the water) and have an assistant open a tap on the filling loop to ensure you get a good flow of clean water.
As others have said, the black sludge is very indellible - so take adequate precautions to prevent it getting spilled on carpets etc.
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Roger Mills
Also it seems to kill plants. I inadvertantly emptied a rad onto the newly planted hedge in our front garden and it killed one of the bushes :-(
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Ok thanks all!
I was hoping for a non time consuming solution but maybe I should get a "pro" in. Although I'd imagine it will cost a fair bit of cash. The main problem is not having anyone who can help me. Ok there's the wife, but she won't carry a radiator into the garden with me!
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This job is time consuming and difficult. You need to address the reason why the gunk was there to begin with. See the Sealed CH FAQ for more back ground info.
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Ed Sirett
Why not? My wife not only helped me carry the radiators out but she cleaned up the black inky sludge that we had dripped on the way!
It's an easy job when the system is drained down and will save you £££'s and be more effective than chemical treatments.
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Another system that may work (probably not quite as well) but is less hassle and less messy:
1) Go round and close all the inlet and outlet taps on all radiators. Make a note of the number of turns to close the lockshield valve on each rad so that you can restore the position later (to maintain balancing).
2) Make sure the drain point is open (and connected to a hose if required etc). Open both taps on one radiator.
3) Then turn the system filling loop tap on. This should force mains cold water through the one rad and out of the drain. Keep an eye on the pressure gauge and make sure it does not rise beyond say 2.5 bar turn down the filling loop tap a bit if it gets close.
4) Watch the drain water until it runs clear.
5) Turn off the filling loop, and close both valves on that rad, and open the valves on the next rad.
6) go back to step 3 until all rads are done.
If you want to get flash, you could leave the filling loop on and open the next rad before going back and closing the previous each time.
Finally restore the rad lockshield valves to their original positions.
For completeness you could then add a flushing agent like sentinel x400 and leave that in for a week before repeating the process again.
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John Rumm
In article , John Rumm writes
Yep, top idea, concentrating mains flow and pressure on one rad at a time should erode a pile of sludge in the bottom of a rad after a while and 30mins concentrated flow per rad would be no hardship on a Sunday diy job. To be effective I think it needs a way of isolating flow through the boiler otherwise it'll short circuit the flow in the radiator, my own system has one in by design but it would be worth the o/p installing a full flow ball valve in the boiler flow for just to make this possible.
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On Tue, 29 Jan 2008 06:33:35 -0800 (PST)
Strange, I would expect it to be mostly ferric sulphide. I didn't think that would be toxic to plants - iron salts are usually beneficial. You live and learn. Thanks.
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If it's a sealed (pressurised) system, when you open the upstairs rads you'll get water coming out.
Also, seeing as you have a mains feed you can flush each rad in situ with a hose on a drain valve somewhere. It's not as good as taking them off but it'll help.
Usual disclaimers etc for primatic systems.
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I'm going to go with this idea first (although I'm not too worried about removing rads and flushing in the garden with more pressure), I am stopping off at a diy place to pick up some system cleaner and the corrosion protection stuff tonight as well.
There is a drain point which seems to be located up at the same height of the boiler. The boiler is in the kitchen so the drain point is around 5 feet off the floor. I thought it would be at floor level or is that just open systems?
Does this sound like the drain point or could it have some other use? (It certainly looks like the drain point :)
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Unfortunately she's going to be too tired after helping me lift the three new kitchen cabinets onto the wall on Sat ;-)
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That could just be the drain for the boiler itself. Have a look at the low level pipes and also at the rad valves - some have built in drain points.
If you need to add a low level drain point, then you can use a self cutting washing machine tap in the first instance. The posh solution is to plumb in a drain point that feeds through a wall to a outside gully and is controlled from a service valve.
Reply to
John Rumm

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